Decentralized Chat with Peer Reputation

Problem: Many chat apps lack spam resistance in open groups.

Idea: Implement a chat dApp using gossipsub where nodes use peer scoring (from your PR!) and peerstore to remember which peers were trustworthy across sessions.

Hack Value: Combines NAT traversal (connectivity) + peerstore (identity/reputation persistence) + peer scoring.

Demo Impact: Show how bad actors get down-scored and their messages ignored, while good peers stay connected even after network changes.

Required Outcome: We will add the top 5 implementations at the main py-libp2p repository (new section: product-innovation).